/*トップページcss*/

:root {
  --header-height: 42%; /* ヘッダーの高さを変数として管理 */
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
}

.top_background {
  height: var(--header-height);
}


body{
  background-color:#ffff7f;
  //font-family: "BIZ UDPGothic", sans-serif;
  font-family: "メイリオ", Meiryo, "ヒラギノ角ゴ Pro W3", "Hiragino Kaku Gothic Pro", Osaka, "ＭＳ Ｐゴシック", "MS PGothic", sans-serif;
  font-weight: 700;
  letter-spacing: 5px;
}
#wrapper{
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}
.top_main{
  margin-top:106px;
  display: flex;
}
.top_contents {
  width:100vw;
}

/*トップ画像*/
.top_background{
  width:100vw;
  height:0;
  padding-top: calc(1050 / 2500 * 100%); /* calc(画像高さ ÷ 画像横幅 × 100%) */
  background-image:url("../image/top.png");
  background-repeat: no-repeat;
  background-size: 100vw auto;
  	scroll-padding-top: 604px;

}

/*Greeting部分*/
.greetinghead{
  width:300px;
  margin: 0 auto;
  padding-top:90px;
  background: rgba(255, 0, 0, 1.0);
}
.greetinghead span {
  position: relative;
  z-index: 1;
  font-size: 40px;
}
.greeting_sentence{
  color: #000000;
  font-size: 15px;
  text-align: center;
  padding-left: 10vw;
  padding-right: 10vw;
  font-weight: normal;
  padding-bottom: 50px;
}
/*Greeting見出し部分*/
h2 {
  position: relative;
  padding: 1.5rem;
  text-align: center;
  border: 2px solid #000;
  background: #fff;
}
h2:before,
h2:after {
  position: absolute;
  content: '';
}
h2:before {
  top: -40px;
  left: calc(50% - 43px);
  width: 80px;
  height: 80px;
  border: 2px solid #000;
  border-radius: 50%;
  background: #fff;
}
h2:after {
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: #fff;
}
h2 i {
  font-size: 3rem;
  font-size: 50px;
  line-height: 60px;
  position: absolute;
  z-index: 1;
  top: -30px;
  left: calc(50% - 40px);
  width: 80px;
  height: 60px;
  text-align: center;
}

/*各ページへのリンク*/
.top_contents a {
  position: relative;
  display: inline-block;
  text-decoration: none;
  color:#000;
}
.top_contents a::after {
  position: absolute;
  bottom: -2px;
  left: 0;
  content: '';
  width: 100%;
  height: 4px;
  background: #000;
  opacity: 0.25;
  transition: .3s;
}
.top_contents a:hover::after {
  bottom: -1px;
  opacity: 1;
  visibility: visible;
}
.top_subcontents_mask{
  height:100%;
  background: rgba(255, 255, 255, 0.25);
  text-align: center;
  color: rgba(255, 255, 255, 0);
}
.top_subcontents_mask:hover{
  height:100%;
  background: rgba(255, 255, 255, 0.5);
  color: rgba(0, 0, 0, 1);
}
.top_subcontents_title{
  color: #000000;
  font-size: 50px;
  padding-top: 150px;
  text-align: center;
}
/*RESEARCH画像*/
.top_subcontents1{
  width: 100%;
  height:400px;
  background-image:url("../image/Kinect.png");
  background-size: cover;
  background-position: 0 50%;
}
/*PUBLICATION画像*/
.top_subcontents2{
  width: 100%;
  height:400px;
  background-image:url("../image/publication.png");
  background-size: cover;
  background-position: 0 70%;
}
/*MEMBER画像*/
.top_subcontents3{
  width: 100%;
  height:400px;
  background-image:url("../image/member.png");
  background-size: cover;
  background-position: 0 25%;
}
/*LINK画像*/
.top_subcontents4{
  width: 100%;
  height:400px;
  background-image:url("../image/link.png");
  background-size: cover;
  background-position: 0 50%;
}

/*ウィンドウサイズ別の指定*/
@media screen and (max-width:1000px){
  /*画面サイズが1000px以下の場合に適用*/
  .top_main{
    margin-top:62px;
  }
}
@media screen and (max-width:628px){
  /*画面サイズが628px以下の場合に適用*/
  .top_main{
    margin-top:114px;
  }
}